Ultra-sensitive, ultra-low power RF field sensor

A sensor includes a hollow enclosure, an antenna disposed external to the hollow enclosure and configured to collect emission of electromagnetic energy, a circuit disposed within the hollow enclosure and comprising a low noise amplifier (LNA) connectable to the antenna, and an analog to digital converter (ADC) in a connection with the LNA, circuit connections connecting, during use of the sensor, the circuit to each of the antenna, a source of electric energy and a signal processing component, a connection between the enclosure and an enclosure of an integrated circuit (IC), whereby the antenna id disposed between the sensor and the IC, and the sensor configured to at least measure a low-level electromagnetic energy emitted from the IC.